List of top Surveying Questions on Levels and Levelling asked in GATE CE

Which one of the following statements is TRUE with respect to levelling survey?

For the traverse given below, the benchmark is at ground point L. The Reduced Level (RL) of L is 150.000 m. The direction of the traverse is from L to N. The readings on levelling staff using the same levelling instrument kept at Stations S1 and S2 during the traversing are shown in the figure.

Column 1	Column 2
	(P) 3.300 m
(I) Sum of Back Sights	(Q) 2.500 m
(II) Sum of Fore Sights	(R) 150.300 m
(III) RL of Point N	(S) 3.000 m
	(T) 150.500 m

Matching the information given under Column 1 and Column 2, which one of the following options is CORRECT?

The following consecutive staff readings (in m) were taken with a dumpy level and a levelling staff at a common interval of 20 m: 0.385; 1.030; 1.925; 2.825; 3.730; 4.850; 1.045; 2.005; 3.330; 4.580. The dumpy level was shifted after taking the sixth reading. The gradient (in %) of the ground between the first and the last location of the readings is ______ (in integer).

Locations \(P\) and \(Q\) are separated by a wide valley. The difference in levels of locations \(P\) and \(Q\) measured by a levelling instrument stationed near \(P\) is 3.0 m. The same instrument stationed near \(Q\) measures the difference in levels of locations \(P\) and \(Q\) as \(-1.0\) m. Assume that the atmospheric refraction is the same during the measurements. The true difference in levels (in m) of locations \(P\) and \(Q\) is

The height of the plane of collimation of a levelling instrument is 100.000 m from a datum. The levelling instrument measures a Back Sight of 1.500 m on a vertically held staff at a ground point \(P\). The reduced level (in m) of the ground point \(P\) with respect to the datum is (rounded off to three decimal places).